/*
 * Copyright (c) 2007-2012, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: FuncId.java,v 1.2.4.1 2005/09/14 20:18:45 jeffsuttor Exp $
 */
package com.sun.org.apache.xpath.internal.functions;

import java.util.StringTokenizer;

import com.sun.org.apache.xml.internal.dtm.DTM;
import com.sun.org.apache.xml.internal.dtm.DTMIterator;
import com.sun.org.apache.xml.internal.utils.StringVector;
import com.sun.org.apache.xpath.internal.NodeSetDTM;
import com.sun.org.apache.xpath.internal.XPathContext;
import com.sun.org.apache.xpath.internal.objects.XNodeSet;
import com.sun.org.apache.xpath.internal.objects.XObject;
import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;

/**
 * Execute the Id() function.
 * @xsl.usage advanced
 */
public class FuncId extends FunctionOneArg {
    static final long serialVersionUID = 8930573966143567310L;

    /**
     * Fill in a list with nodes that match a space delimited list if ID
     * ID references.
     *
     * @param xctxt The runtime XPath context.
     * @param docContext The document where the nodes are being looked for.
     * @param refval A space delimited list of ID references.
     * @param usedrefs List of references for which nodes were found.
     * @param nodeSet Node set where the nodes will be added to.
     * @param mayBeMore true if there is another set of nodes to be looked for.
     *
     * @return The usedrefs value.
     */
    private StringVector getNodesByID(XPathContext xctxt, int docContext, String refval, StringVector usedrefs, NodeSetDTM nodeSet, boolean mayBeMore) {

        if (null != refval) {
            String ref = null;
            //      DOMHelper dh = xctxt.getDOMHelper();
            StringTokenizer tokenizer = new StringTokenizer(refval);
            boolean hasMore = tokenizer.hasMoreTokens();
            DTM dtm = xctxt.getDTM(docContext);

            while (hasMore) {
                ref = tokenizer.nextToken();
                hasMore = tokenizer.hasMoreTokens();

                if ((null != usedrefs) && usedrefs.contains(ref)) {
                    ref = null;

                    continue;
                }

                int node = dtm.getElementById(ref);

                if (DTM.NULL != node)
                    nodeSet.addNodeInDocOrder(node, xctxt);

                if ((null != ref) && (hasMore || mayBeMore)) {
                    if (null == usedrefs)
                        usedrefs = new StringVector();

                    usedrefs.addElement(ref);
                }
            }
        }

        return usedrefs;
    }

    /**
     * Execute the function.  The function must return
     * a valid object.
     * @param xctxt The current execution context.
     * @return A valid XObject.
     *
     * @throws javax.xml.transform.TransformerException
     */
    public XObject execute(XPathContext xctxt) throws javax.xml.transform.TransformerException {

        int context = xctxt.getCurrentNode();
        DTM dtm = xctxt.getDTM(context);
        int docContext = dtm.getDocument();

        if (DTM.NULL == docContext)
            error(xctxt, XPATHErrorResources.ER_CONTEXT_HAS_NO_OWNERDOC, null);

        XObject arg = m_arg0.execute(xctxt);
        int argType = arg.getType();
        XNodeSet nodes = new XNodeSet(xctxt.getDTMManager());
        NodeSetDTM nodeSet = nodes.mutableNodeset();

        if (XObject.CLASS_NODESET == argType) {
            DTMIterator ni = arg.iter();
            StringVector usedrefs = null;
            int pos = ni.nextNode();

            while (DTM.NULL != pos) {
                DTM ndtm = ni.getDTM(pos);
                String refval = ndtm.getStringValue(pos).toString();

                pos = ni.nextNode();
                usedrefs = getNodesByID(xctxt, docContext, refval, usedrefs, nodeSet, DTM.NULL != pos);
            }
            // ni.detach();
        } else if (XObject.CLASS_NULL == argType) {
            return nodes;
        } else {
            String refval = arg.str();

            getNodesByID(xctxt, docContext, refval, null, nodeSet, false);
        }

        return nodes;
    }
}
